A Photonic Crystal Fiber Based Gold-Coated Open Channel SPR Sensor for Low RI Detection

An incredibly sensitive surface plasmon resonance (SPR) sensor has been featured in this paper, with relatively simple construction to provide practical implementation feasibility. The sensor has been implanted with a microchannel. It can detect analytes within the low sensing range of 1.20 -1.33, making it suitable for detecting pharmaceutical agents, organic compounds like halogenated ether, various refrigerants, and many more. Due to its chemical stability, gold has been employed as the plasmonic material layer for the sensor externally to induce surface plasmon resonance in the external surface of the photonic crystal fiber (PCF). A circular perfectly matched layer has been applied to the sensor’s outermost layer as a boundary condition to absorb surface back radiation. Through simulations based on COMSOL Multiphysics and numerical analysis based on the Finite Element Method, it was discovered that the suggested sensor attained a maximum wavelength sensitivity of 295,000 nm/RIU, which is the highest achieved sensitivity among the recently reported sensors in the literature. Moreover, the sensor has achieved the most excellent amplitude sensitivity of 1197 RIU-1. Furthermore, the suggested sensor’s minimum resolution has been determined to be 1.83×10
^-7
RIU, assuring superior analyte detection accuracy, while the most excellent Figure of Merit (FOM) has been determined to be 2107 RIU
^-1
. As a result, the suggested sensor might be used to correctly detect biochemical analytes, pharmaceutical inspections, and medical diagnoses.